A shield electric cable has a core wire for transmitting electric power and signals, that is covered with a shield layer with an insulating layer therebetween, thereby preventing the core wire from being a noise source at the electric power transmission or preventing an external noise from being superimposed on the core wire of the shield electric cable. In other words, the shield electric cable is secured of electromagnetic shield characteristics by the shield layer.
In case that such a shield electric cable is connected to a mate member, such as another shield electric cable and a device, a shield electric cable connector is fixed to the peeled terminal portion of the shield electric cable to retain the shield characteristics. This type of shield electric cable connector is disclosed, for example, in Japanese Patent Laid-Open Publication No. 6-260246. The disclosed shield electric cable connector has a shield pipe covering the peeled terminal portion of a shield electric cable and having a tip end that is electrically connected to the shield of a mate member. The shield electric cable connector further has a sleeve into which the shield layer exposed at the terminal portion of the shield electric cable is inserted, thereby electrically connecting the exposed shield layer and the base end of the shield pipe. More specifically, the sleeve is formed to have steps and has a large diameter portion contactable with the shield pipe, a small diameter portion fastened upon the exposed shield layer by caulking, and a middle diameter portion fastened upon a sheath by caulking between the large and small diameter portions.
When the shield electric cable connector disclosed in the publication is attached to a shield electric cable, however, an operator is required to do vexatious and complicated work of inserting the terminal portion of the shield electric cable into the sleeve and then caulking the sleeve. Moreover, such work is unsuitable for automation utilizing machine, or mass production.
As for the shield electric cable connector described in the publication, there is a wide variation in the contact state between the exposed shield layer and the small diameter portion of the sleeve with respect to each connector depending on the accuracy of the caulking work itself. Thus, there is fear that there occurs a variation in shield characteristics. If the sheath is deteriorated to shrink under the influence of heat, and the contact state between the sheath and the middle diameter portion of the sleeve becomes unstable, the sleeve cannot be firmly attached to the shield electric cable, resulting in a potential decline in the shield characteristics.